U.S. patent application number 12/706150 was filed with the patent office on 2010-06-10 for systems and methods for compressing and distracting vertebrae of the spinal column.
This patent application is currently assigned to WARSAW ORTHOPEDIC, INC.. Invention is credited to Arthur Conley, Roy Lim, Anthony J. Melkent.
Application Number | 20100145349 12/706150 |
Document ID | / |
Family ID | 35159888 |
Filed Date | 2010-06-10 |
United States Patent
Application |
20100145349 |
Kind Code |
A1 |
Lim; Roy ; et al. |
June 10, 2010 |
Systems and Methods for Compressing and Distracting Vertebrae of
the Spinal Column
Abstract
Spinal surgical systems include a compressor mountable to a
first vertebra and positionable relative to a fulcrum mountable to
a second vertebra. The compressor and fulcrum are manipulated
relative to one another to compress the first and second vertebrae.
The systems further include a distractor mountable to a first
vertebra and positionable relative to a fulcrum mountable to a
second vertebra. The distractor and fulcrum are manipulated
relative to one another to distract the first and second
vertebrae.
Inventors: |
Lim; Roy; (Germantown,
TN) ; Conley; Arthur; (Edmond, OK) ; Melkent;
Anthony J.; (Memphis, TN) |
Correspondence
Address: |
MEDTRONIC;Attn: Noreen Johnson - IP Legal Department
2600 Sofamor Danek Drive
MEMPHIS
TN
38132
US
|
Assignee: |
WARSAW ORTHOPEDIC, INC.
Warsaw
IN
|
Family ID: |
35159888 |
Appl. No.: |
12/706150 |
Filed: |
February 16, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10885265 |
Jul 6, 2004 |
7686814 |
|
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12706150 |
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Current U.S.
Class: |
606/90 |
Current CPC
Class: |
A61B 17/025 20130101;
A61B 17/7079 20130101; A61B 17/8866 20130101; A61B 17/8019
20130101; A61B 2017/0256 20130101 |
Class at
Publication: |
606/90 |
International
Class: |
A61B 17/60 20060101
A61B017/60 |
Claims
1-26. (canceled)
27. A distractor, comprising: an elongated body extending along a
longitudinal axis between a proximal end and a distal leverage
surface, said elongated body including a channel between said
proximal end and said distal leverage surface; an angled extension
extending distally from said distal leverage surface of said
elongated body along a distal axis angled relative to said
longitudinal axis, said angled extension defining a distal channel
extending therealong in communication with said channel of said
elongated body; and an engaging member extending distally from said
angled extension, said engaging member being positionable adjacent
an anchor engaged to a bony portion of a patient's body.
28. The distractor of claim 27, wherein said engaging member
includes a U-shaped recess formed in a distal end surface
thereof.
29. The distractor of claim 27, wherein said engaging member
includes a flat plate-like extension extending from said distal
angled portion.
30. The distractor of claim 27, wherein said elongated body
includes a convexly curved outer surface opposite said channel.
31. The distractor of claim 27, wherein said channel of said
elongated body is defined by a concavely curved surface extending
between opposite sides of said elongated body.
32. The distractor of claim 31, wherein said angled extension
includes a convexly curved outer surface opposite said distal
channel.
33. The distractor of claim 32, wherein said distal channel of said
angled extension is defined by a concavely curved surface extending
between opposite sides of said angled extension.
34. The distractor of claim 27, wherein said distal leverage
surface extends between said channel of said elongated body and
said channel of said distal angled portion, said distal leverage
surface being contactable with an elongated shaft of a fulcrum to
move said engaging member away from said fulcrum as said proximal
end of said elongated body is moved toward said fulcrum.
35.-41. (canceled)
42. A spinal surgical system, comprising: a distractor including an
elongated body extending between a proximal end and a leverage
surface, said distractor further comprising an angled extension
extending distally from said elongated body along a distal axis
angled relative to said longitudinal axis and an engaging member
extending distally from said angled extension, said engaging member
being engageable to a first vertebra; and a fulcrum including an
elongated shaft extending between a proximal end and a distal end,
said distal end being engageable to a second vertebra, said fulcrum
being removably and nestably received by said distractor with said
elongated shaft in contact with said leverage surface of said
distractor, said distractor and said fulcrum having a first
configuration wherein said distal end of said fulcrum is positioned
to a first side of and adjacent to said engaging member of said
distractor and said proximal end of said fulcrum is positioned to
said first side of and spaced from said proximal end of said
distractor, wherein movement of said proximal ends of said
distractor and said fulcrum toward one another moves said engaging
member of said distractor and said distal end of said fulcrum away
from one another about said leverage surface.
43. The system of claim 42, wherein said leverage surface is
contactable with said elongated shaft at any one of a number of
locations along said elongated shaft when in said first
configuration.
44. The system of claim 42, wherein said elongated body and said
angled extension each include a channel oriented toward said
fulcrum in said first configuration.
45. The system of claim 44, wherein said elongated shaft of said
fulcrum is received in said channel of said distal extension in
said first configuration.
46. The system of claim 45, wherein said elongated shaft is
positioned along said channel of said elongated body as said
proximal ends of said distractor and said fulcrum are moved toward
one another.
47. The system of claim 44, wherein said leverage surface is formed
at a junction of said channels of said elongated body and said
angled extension.
48. The system of claim 42, wherein said engaging member of said
distractor includes a flat, plate-like body.
49. The system of claim 48, wherein said engaging member includes a
recess in a distal end surface of said flat, plate-like body.
50. The system of claim 42, further comprising: a construct
including an elongated connecting member extending between the
first and second vertebrae and first and second anchors for
engaging the connecting member between the first and second
vertebrae, wherein said distractor and said fulcrum are mountable
to respective ones of the first and second anchors, said elongated
connecting member being movable along at least one of said anchors
when said proximal ends of said fulcrum and said distractor are
moved toward one another to move said engaging member of said
compressor and said distal end of said fulcrum away from one
another to distract the first and second vertebrae.
51.-56. (canceled)
57. A method for distracting vertebrae, comprising: positioning a
distractor and a fulcrum through a portal to the vertebrae;
mounting the fulcrum to a first vertebra; mounting the distractor
to a second vertebra; positioning the fulcrum against a leverage
surface of the distractor; and pivoting the distractor and fulcrum
relative to one another about the leverage surface by moving
proximal ends of the distractor and fulcrum toward one another to
move distal ends of the distractor and fulcrum away from one
another thereby distracting the vertebrae.
58. The method of claim 57, wherein the leverage surface is
positionable at any one of a number of locations along the
fulcrum.
59. The method of claim 57, wherein the leverage surface is formed
between a proximal channel and a distal channel opening along one
side of the distractor, the distal channel being angled relative to
the proximal channel.
60. The method of claim 59, wherein positioning the fulcrum against
the leverage surface of the distractor includes positioning the
fulcrum in the distal channel of the distractor.
61. The method of claim 60, wherein pivoting the distractor and
fulcrum relative to one another includes moving the proximal
channel toward the fulcrum.
62. The method of claim 57, wherein mounting the fulcrum and
mounting the distractor each include mounting the fulcrum and
mounting the distractor to an anchor engaged to respective ones of
the first and second vertebrae.
63. The method of claim 57, further comprising engaging a
connecting member between the first and second anchors when a
desired distraction between the first and second vertebrae is
obtained.
Description
BACKGROUND
[0001] Orthopedic devices such as spinal rods, plates, tethers,
staples and other devices can be secured along the spinal column
between one or more vertebral levels to stabilize the one or more
vertebral levels. While surgical procedures along the spinal column
for placement of such devices are becoming less invasive, the
decrease in space available in the approach to the surgical site
and at the surgical site for handling and manipulating of the
devices increases the difficulty in maneuvering, maintaining and
finally positioning of the devices during the procedure.
Furthermore, the ability to manipulate the vertebrae of the spinal
column by compressing or distracting the vertebrae before
attachment of the orthopedic devices is hindered by the construct
attached to the vertebrae, the complexity and size of the footprint
of the instruments involved in delivering the compression or
distraction forces, the desire to maintain a minimally invasive
approach to the spinal column, the vital anatomical structures
adjacent the surgical site, and other factors.
BRIEF DESCRIPTION OF THE FIGURES
[0002] FIG. 1 is a view of a compression system positioned through
a portal and mounted to a construct engaged to the spinal
column.
[0003] FIG. 2 is a top view of the portal and construct of FIG. 1
showing a compressor of the compression system inserted through the
portal and mounted to an anchor.
[0004] FIG. 3 is a view of the portal, construct and compressor of
FIG. 2 with a fulcrum being positioned through the compressor.
[0005] FIG. 4 is a view showing the compressor and fulcrum in the
portal and mounted to the construct before compression of the
spinal column.
[0006] FIG. 5 is a view showing engagement of the distal portions
of the compressor and fulcrum mounted with the construct before
compression of the spinal column.
[0007] FIG. 6 is ad view showing engagement of the distal portions
of the compressor and fulcrum mounted with the construct after
compression of the spinal column.
[0008] FIG. 7 is a view of the portal and another embodiment
construct engaged to the spinal column.
[0009] FIG. 8 is a view showing another embodiment compressor being
positioned through the portal for mounting with the construct of
FIG. 7.
[0010] FIG. 9 is a view showing another embodiment fulcrum being
positioned through the portal and compressor for mounting with the
construct of FIG. 7.
[0011] FIG. 10 is a view showing the compressor and fulcrum through
the portal mounted to the construct of FIG. 7.
[0012] FIG. 11 is a top view showing the compressor and fulcrum
through the portal and mounted to the construct of FIG. 7.
[0013] FIG. 12 is a view showing the compressor and fulcrum through
the portal and mounted to the construct of FIG. 7 before
compression of the spinal column.
[0014] FIG. 13 is a view showing the compressor and fulcrum through
the portal and mounted to the construct of FIG. 7 after compression
of the spinal column.
[0015] FIG. 14 is a view of the construct of FIG. 7 and the distal
portions of the fulcrum and compressor mounted thereto after
compression of the spinal column.
[0016] FIG. 15 is a perspective view of a distractor.
[0017] FIG. 16 is a view of a distal portion of the distractor.
[0018] FIG. 17 is a view of a portal and a construct engaged along
the spinal column.
[0019] FIG. 18 is a view of a fulcrum mounted to the construct of
FIG. 17 through the portal.
[0020] FIG. 19 is a view of the distractor and fulcrum through the
portal mounted to the construct of FIG. 17.
[0021] FIG. 20 is a view of the distal portions of the distractor
and fulcrum mounted to the construct of FIG. 17 before distraction
of the spinal column.
[0022] FIG. 21 is a view of the distractor and fulcrum through the
portal mounted to the construct of FIG. 17 after distraction of the
spinal column.
[0023] FIG. 22 is an enlarged view of the distal portions of the
distractor and fulcrum mounted to the construct after distraction
of the spinal column.
DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS
[0024] For the purposes of promoting an understanding of the
principles of the invention, reference will now be made to the
embodiments illustrated in the drawings and specific language will
be used to describe the same. It will nevertheless be understood
that no limitation of the scope of the invention is thereby
intended. Any such alterations and further modifications in the
illustrated devices and described methods, and any such further
applications of the principles of the invention as illustrated
herein are contemplated as would normally occur to one skilled in
the art to which the invention relates.
[0025] Systems for applying compression and distraction to
vertebrae of the spinal column include, in one embodiment, a
compressor mountable to a first vertebra and a fulcrum mountable to
a second vertebra. The compressor includes an elongated body having
an intermediate opening to receive an elongated shaft of the
fulcrum therethrough such that when assembled the compressor and
fulcrum have a nested configuration where their longitudinal axis
cross one another at a location between their distal and proximal
ends. Compression of the vertebrae is performed by moving the
proximal ends of the compressor and fulcrum toward one another,
which moves the distal ends of the compressor and fulcrum toward
one another. The body of the compressor contacts the shaft of the
fulcrum along a leverage surface adjacent the opening of the
compressor, allowing the compressor to be leveraged with the
fulcrum.
[0026] In another embodiment, a system includes an elongated
compressor and an elongated fulcrum, which are positionable
independently of one another through an operative approach to first
and second vertebrae. The fulcrum and compressor are mountable to
respective ones of the first and second vertebrae. The compressor
and fulcrum are configured to nest with one another so that the
compressor can be leveraged with the fulcrum to deliver a
compression force between the first and second vertebrae.
[0027] In another embodiment, a system includes a distractor having
an elongated body with a distal end mountable to a first vertebra,
and a fulcrum having an elongated shaft with a distal end mountable
to a second vertebra. The distractor includes a proximal handle
portion and distal portion that is angled relative to the proximal
portion away from the fulcrum when each is mounted to the
respective vertebra. The distractor includes a leverage surface
between the proximal handle portion and the distal angled portion
that is positionable against the fulcrum such that at least the
proximal ends of the distractor and fulcrum are separated from one
another. The proximal ends of the distractor and fulcrum are
moveable toward one another to move the distal ends of the
distractor and fulcrum away from one another to distract the
vertebrae. A mechanical advantage is provided by leveraging the
distractor with its leverage surface against the shaft of the
fulcrum.
[0028] In another embodiment, a system includes an elongated
distractor and an elongated fulcrum, which are positionable
independently of one another through an operative approach to first
and second vertebrae. The fulcrum and distractor are separately
mountable to the first and second vertebrae. The distractor and
fulcrum are configured to act upon one another so that the
distractor can be leveraged off of the fulcrum to deliver a
distraction force between the first and second vertebrae.
[0029] In one embodiment, the distal end of the compressor or
distractor is mountable to an anchor engaged to the first vertebra,
and the distal end of the fulcrum is mountable to an anchor engaged
to the second vertebra. A connecting member extends between the
first and second anchors, and is secured between the anchors when
the desired compression or distraction has been obtained. The
connecting member can be a rod, plate, staple, flexible member or
other suitable device positionable to extend between vertebrae and
engageable to the vertebrae.
[0030] The systems can be employed in minimally invasive approaches
to the vertebrae. In one embodiment, the minimally invasive
approach is provided by a tubular retractor inserted through the
tissue to provide a protected passageway to the first and second
anchors. In a further embodiment, the tubular retractor is
expandable to increase the size of the working space adjacent the
first and second vertebrae relative to the size of the incision
through which the retractor is inserted. In another embodiment, the
approach is provided by one or more retractor blades inserted
through the incision to provide a pathway to the first and second
vertebrae. In another embodiment, the systems are employed directly
through the tissue through one or more micro-incisions. In another
embodiment, the first and second vertebrae are exposed in an open
surgical technique and the systems are employed through the
incision and retracted tissue providing the open approach.
[0031] The first and second vertebrae can be adjacent vertebrae of
the spinal column, or can be vertebrae separated from one another
by one or more intervening vertebrae. The approach to the vertebrae
can be anterior, posterior, lateral, oblique, postero-lateral, or
any other suitable approach. The first and second vertebrae can be
located along any one or combination of regions of the spinal
column, including the cervical, thoracic, lumbar and sacral
regions.
[0032] Referring to FIG. 1 therein shown a minimally invasive
access portal 200 positioned through skin and tissue 202. Access
portal 200 provides a pathway to the spinal column, including first
vertebra 204 and second vertebra 206 and spinal disc space 208
therebetween. In the illustrated embodiment, access portal 200 is
an expandable tubular retractor such as is described in U.S. Patent
Application Publication No. 2003/0191371 A1, which is incorporated
herein by reference. The expandable tubular retractor provides a
portal that defines a protected passageway to the spinal column.
The tubular retractor includes a first insertion configuration in
which the retractor is cylindrical and is moveable in situ to a
second configuration in which the distal end of the retractor is
enlarged to form a proximally tapered working channel between the
distal and proximal ends of the retractor. However, as discussed
above, any suitable instrument, technique, or retractor for
accessing the spinal column is contemplated. In addition, vertebrae
204, 206 need not be directly adjacent vertebrae, and can be
separated by one or more other vertebrae.
[0033] A construct 210 is engaged to vertebrae 204, 206 and extends
therebetween. In the illustrated embodiment of FIG. 1, construct
includes a first anchor 212 engaged to first vertebra 204, a second
anchor 214 engaged to second vertebra 206, and a connecting member
216 extending between first and second anchors 212, 214. Anchors
212, 214 can be multi-axial type screws with a first portion (not
shown) including a screw member threadingly engageable to the
respective vertebra, and a second portion with a receiver member
pivotally mounted to an enlarged head of the screw member.
Connecting member 216 is an elongated rod received in passages of
the receiver members of the anchors. The rod can be secured in the
receiver members with a plug that is engaged to respective ones of
the receiver members to firmly seat the rod against a bottom
surface of the receiver member.
[0034] Other forms for the construct are contemplated. For example,
the anchors can be uni-axial screws, bolts, hooks, staples, spikes,
interbody devices, fusion devices or cages, artificial disc
devices, or other suitable structure including a first portion for
engaging one or more vertebrae and a second portion for engaging
the connecting member. The connecting member can be a plate, strut,
tether, staple, spacer or other suitable device for extending
between two or more anchors. Furthermore, the construct can be
arranged to extend between more than two vertebrae, and can be
engaged to three or more anchors. The plug can be a set screw, cap,
or other device that engages the construct to the anchor.
[0035] FIGS. 1-6 show a compressor system 30 that is mountable to
vertebrae 204, 206 and manipulatable relative thereto to deliver a
compressive force between vertebrae 204, 206. When the desired
compression force has been applied, construct 210 is secured
between vertebrae 204, 206 to maintain the compression
post-operatively. In the illustrated embodiment, system 30 is
mountable to anchors 212, 214 engaged to respective ones of the
vertebrae 204, 206. It is also contemplated that system 30 can be
mounted directly to vertebrae 204, 206; or mounted to a secondary
fastener or device engaged to vertebrae 204, 206 which does not
form a part of the construct 210.
[0036] System 30 includes a compressor 40 mountable to first
vertebra 204. Compressor 40 includes an elongated body 42 extending
along a longitudinal axis 41 between a proximal end 44 and a
distally oriented leverage surface 46. A pair of arms 48 extends
distally from body 42. Arms 48 define an opening 58 therebetween.
An engaging member 50 is provided at the distal ends of arms 48 and
extends between arms 48. As shown in FIG. 2, engaging member 50 is
offset laterally relative to arms 48 by a pair of extensions 60
extending transversely to and laterally from respective ones of the
arms 48 and an end member extending between extensions 60. Arms 48
and engaging member 50 form a receptacle 51 for receiving a portion
of an anchor engaged to a vertebra therein. In the illustrated
embodiment, receptacle 51 includes a generally rectangular shape
that receives the receiver member of anchor 212 in a manner that
prevents the receiver member from rotating relative to engaging
member 50. Other shapes for receptacle 51 are also contemplated,
including omitting receptacle 51, so long as engaging member 50 is
capable of engaging an anchor or a vertebra.
[0037] Body 42 further includes opposing sidewalls 56 extending
therealong, and a channel 52 extending between sidewalls 56.
Channel 52 includes a U-shape formed by a concavely curved surface
sized to receive elongated shaft 72 of fulcrum 70 therein; however,
other shapes are also contemplated. Body 42 includes an outer
surface 54 opposite channel 52 having a convex curvature to
facilitate gripping of body 42. Outer surface 54 can also be
non-curved, and include grip-enhancing features such as knurling,
indentations, protrusions or the like.
[0038] Compression system 30 further includes a fulcrum 70 nestably
positioned relative to compressor 40 and mountable to second
vertebra 206. Fulcrum 70 includes an elongated shaft 72 extending
along a longitudinal axis 82 between a proximal end 74 and a distal
engaging member 76. Elongated shaft 72 defines a passage 75
extending therethrough. Handle 78 extends from proximal end 74
along a handle axis 80. Handle axis 80 is oriented transversely to
longitudinal axis 82. In the illustrated embodiment, handle axis 80
is orthogonal to longitudinal axis 82; however, other transverse
orientations are also contemplated. The transverse orientation of
handle 78 facilitates maneuvering and gesturing of the fulcrum 70
through portal 200. The transverse orientation of handle 78 also
maintains access to passage 75. In other embodiments, elongated
shaft 72 does not include a passage 75, but rather is solid.
[0039] Passage 75 can extend through engaging member 76. Passage 75
includes a distally oriented opening in engaging member 76 that is
structured to receive the receiver member of the anchor to which it
is engaged therein. As shown in FIG. 3, the sides of engaging
member 76 can be enlarged relative to the shaft 72 so as to extend
about the head of the receiver members. Fulcrum 70 is oriented so
that engaging member 76 can be positioned through opening 58 of
compressor 40. In FIG. 4, fulcrum 70 is rotated 90 degrees about
longitudinal axis 82 relative to its FIG. 3 orientation to align
engaging member 76 with the receiver member of anchor 214. As shown
in FIG. 5, engaging member 76 is positioned about the receiver
member of anchor 214. The distal end of engaging member 76 includes
a distally-oriented recess 84 (FIG. 3) formed therein to receive
connecting element 216 therein when engaging member 76 is fully
seated on the receiver member of anchor 214. The interface between
engaging member 76 and the receiver member of anchor 214 can be
configured so that fulcrum 70 cannot rotate relative to the
receiver member of anchor 214, allowing the alignment of the
receiver member relative to fulcrum 70 to be maintained during the
procedure.
[0040] In use, access portal 200 is positioned to access the spinal
column. Procedures can be performed in disc space 208 or on
vertebrae 204, 206. Such procedures can include one or more of a
discectomy, facectomy, laminectomy, artificial disc placement,
fusion device placement, annulus repair or augmentation, or any
other spinal surgical procedure. Anchors 212 and 214 can be engaged
to respective ones of the vertebrae using any known instruments and
techniques. Connecting member 216 can be positioned through access
portal 200 and positioned in the receiver members of anchors 212,
214. Connecting member 216 is tightly secured to one of the
anchors, such as anchor 212, with a plug engaged to the receiver
member. The plug can be an internally or externally threaded set
screw, nut, washer, cap or any other device or combination of
devices capable of engaging the connecting member in, on, about or
adjacent to the receiver member of the anchor. A second plug can
also be positioned in the receiver member of the other anchor 214
to loosely retain connecting member 216 therein.
[0041] As shown in FIG. 2, compressor 40 is positioned about the
receiver member of anchor 212. Opening 58 is aligned with the
receiver member of anchor 214. In FIGS. 3 and 4, fulcrum 70 is
delivered through portal 220 and opening 58 between arms 48 for
engagement with anchor 214, as shown in FIG. 5. When engaged to
anchor 214, fulcrum 70 is manipulated and nestably positioned
relative to compressor 40 for manipulation relative to one another
to deliver a compressive force to vertebrae 204, 206. The nestable
positioning maintains contact and alignment between compressor 40
and fulcrum 70 during compression of the spinal column.
[0042] In the illustrated embodiment, fulcrum 70 is received
through opening 58 of compressor 40 such that shaft 72 and body
42/arms 48 cross one another. Thus, the longitudinal axes 82, 41 of
fulcrum 70 and compressor 40 form an X-shape in their engaged
positions with anchors 212, 214. Elongated shaft 72 of fulcrum 70
is positioned in contact with leverage surface 46 of elongated body
42, and channel 52 is oriented toward elongated shaft 72 of fulcrum
70. Connecting member 216 is received in recesses 62, 84 of
engaging members 50, 76 of compressor 40 and fulcrum 70,
respectively, when compressor 40 and fulcrum 70 are fully seated on
the respective anchors. Recesses 62, 84 allow engaging members 50,
76 of compressor 40 and fulcrum 70 to be seated further distally on
the receiver members of the anchors, providing a firm grip about
the anchor to maintain engagement during compression of the spinal
column.
[0043] To compress vertebrae 204, 206, the proximal ends 44, 74 of
compressor 40, fulcrum 70 are moved toward one another. Compressor
40 pivots relative to fulcrum 70 due to the contact between
leverage surface 46 and the outer surface of elongated shaft 72 of
fulcrum 70. The location along elongated shaft 72 in contact with
leverage surface 46 to effect pivoting of compressor 40 relative to
fulcrum 70 can vary proximally and distally along shaft 72. The
contact location can vary depending on the separation distance of
anchors 212, 214, the alignment between vertebrae 204, 206, the
orientation of portal 200 relative to vertebrae 204, 206, and the
orientation of compressor 40 and fulcrum 70 relative to one another
and to the anchors 212, 214. Accordingly, compression system 30 has
application even when anchors 212, 214 are not aligned with another
or spaced various distances from one another while still minimizing
the footprint of system 30 through portal 200. As proximal ends 44,
74 are moved toward one another, the distal ends of fulcrum 70 and
compressor 40 move toward one another, compressing vertebrae 204,
206 as shown in FIG. 6.
[0044] As compressor 40 and fulcrum 70 are moved toward one
another, channel 52 of compressor 40 receives elongated shaft 72 of
fulcrum 70. This nesting arrangement further provides a low profile
footprint for compression system 30 through portal 200, allowing
the size of portal 200 to be minimized. Furthermore, receipt of
fulcrum 70 through opening 58 of compressor 40 provides a low
profile footprint extending transversely to connecting member 216
since the longitudinal axes of compressor 40 and fulcrum 70 are
aligned along the axis extending between the receiver members of
anchors 212, 214.
[0045] With connecting member 216 secured tightly in anchor 212
with a plug, connecting member 216 moves relative to anchor 214 as
the vertebrae are compressed, moving anchors 212, 214 toward one
another. When the desired compression has been obtained, the plug
or set screw provisionally engaged to anchor 214 can be tightened
with a driver instrument positioned through passage 75 of fulcrum
70. Alternatively, a plug can be delivered through passage 75 of
fulcrum 70 to engage the connecting member 216 to anchor 214.
Fulcrum 70 can further function as a counter-torque as the plug is
tightened in the receiver member against the connecting member.
Handle 78 can be grasped to prevent the receiver member and/or the
bone engaging portion of anchor 214 from rotating as the plug is
tightened into position. When secured to anchors 212, 214,
connecting member 216 can post-operatively maintain the compression
applied with compressor 40 and fulcrum 70. Compressor 40 and
fulcrum 70 can then be un-mounted from anchors 212, 214 and removed
through portal 200.
[0046] Other embodiments contemplate other nestable arrangements
between fulcrum 70 and compressor 40. For example, compressor 40
and fulcrum 70 can be provided with an nesting configuration in
which compressor 40 and fulcrum 70 extend along side one another,
and include portions that overlap and are contactable with one
another along a leverage surface to effect pivoting of compressor
40 and fulcrum 70 relative to one another. In another example, one
or more of the longitudinal axes of compressor 40 and fulcrum 70
are offset relative to the longitudinal axis of the connecting
member extending between anchors 212, 214.
[0047] Referring to FIGS. 7-14, there is shown another embodiment
compression system 130 that includes a compressor 90 and a fulcrum
120 engageable to another embodiment construct 210. As shown in
FIG. 7, construct 210 includes a first anchor 222 and a second
anchor 224 engageable to first and second vertebrae, such as
vertebrae 204, 206 discussed above. Each of the anchors 222, 224
includes a first portion (not shown) for engaging the vertebra.
Anchors 222, 224 also include a second portion for securing the
connecting member between the vertebrae. In the illustrated
embodiment, the second portion is an enlarged head structure that
clamps or secures the plate-like connecting member 220 to the
respective vertebra. Connecting member 220 includes one or more
central openings 226 through which anchors 222, 224 extend. The
enlarged head structure of the second portion of the respective
anchor bears against the upper surface of connecting member 220 to
secure it to the respective vertebra. The head-like structure can
be integrally formed with a threaded shaft or other body comprising
the first anchor portion that is received through the central
opening 226. The second anchor portion can also be, for example, a
nut, cap or other device that engages connecting member 220 to an
anchor.
[0048] As shown in FIG. 13, compressor 90 includes an elongated
body 92 extending along a longitudinal axis 91 between a proximal
end 94 and a distally oriented leverage surface 96. A pair of arms
98 extends distally from body 92, and an engaging member 100
extends between arms 98 at their distal ends. An opening 108 is
formed between arms 98 to receive the fulcrum therethrough. As
shown in FIG. 8, engaging member 100 extends transversely to arms
98 and forms a receptacle 102 sized and shaped for positioning
about the enlarged head of one of the anchors 222, 224. In the
illustrated embodiment, receptacle 102 is circular. Other
embodiments contemplate other forms and shapes for receptacle 102,
including omitting receptacle 102, so long as engaging member 100
is capable of engaging an anchor or a vertebra. As shown in FIG.
11, body 92 defines a channel 104 along one side thereof. Channel
104 can be U-shaped and defined by a concavely curved surface 106
extending between opposite sides 110. A convexly curved outer
surface 112 opposite channel 104 facilitates the surgeon grasping
compressor 90 during the surgical procedure.
[0049] Another embodiment fulcrum 120 is positionable through
portal 200 and engageable to the other of the anchors 222, 224.
Fulcrum 120 includes an elongate shaft 122 extending between a
proximal end 124 and an opposite engaging member 126 at its distal
end. As shown in FIG. 11, a passage 128 can extend through shaft
122 and open at its distal and proximal ends. Engaging member 126
includes a profile that receives and engages the second portion of
the anchor 222, 224 to which it is mounted. In one embodiment, the
second portion of the anchor is a nut or head and engaging member
126 is configured to engage the nut or head to allow rotational
forces to be applied to the anchor with fulcrum 120.
[0050] Anchors 222, 224 are delivered through portal 200 and
engaged to respective ones of the vertebrae, and connecting member
220 is positioned between anchors 222, 224, as shown in FIG. 7. If
top-loading anchors 222, 224 are provided, the anchors are engaged
to vertebrae 204, 206 before connecting member 220 is delivered and
engaged to the anchors. If bottom loading anchors are provided,
connecting member 220 is positioned along the vertebrae and anchors
222, 224 are positioned through central opening 226 to engage the
connecting member to the vertebrae. In any event, one of the
anchors 222, 224 is tightened to securely engage connecting member
220 to the respective vertebra. In the illustrated embodiment,
anchor 224 is tightened, while anchor 222 is loosely positioned
relative to connecting member 220.
[0051] As shown in FIG. 8, compressor 90 is positioned through
portal 220 with its engaging member 100 oriented toward anchor 224.
In FIG. 9 fulcrum 120 is positioned with its elongated shaft 122
extending through opening 108. Fulcrum 120 and compressor 90 are
manipulated in portal 200 so that engaging member 126 is positioned
about the second portion of anchor 222, and so that engaging member
100 of compressor 90 is positioned about the second portion of
anchor 224. Leverage surface 96 of compressor body 92 is positioned
against elongated shaft 122 of fulcrum 120, as shown in FIGS.
10-12. Compressor 90 and fulcrum 110 are oriented relative to one
another so that proximal ends 94, 124 are spaced from one another.
As shown in FIG. 12, the longitudinal axes 91, 121 of compressor 90
and fulcrum 120 cross one another such that compressor 90 and
fulcrum 120 form an X-shape, and distal engaging members 100, 126
are spaced from one another in a direction opposite the spacing of
proximal ends 94, 124. Fulcrum 120 is nestably positioned relative
to compressor 90 to maintain a low profile footprint for
compression system 130 through portal 200, as discussed above with
respect to compression system 30.
[0052] To compress the vertebrae, proximal ends 94, 124 are moved
toward one another, causing compressor 90 and fulcrum 120 to pivot
relative to one another about their contact location at leverage
surface 96. As the proximal ends 94, 124 move toward one another,
the distal engaging members 100, 126 move anchors 222, 224 and thus
vertebrae 204, 206 toward one another along connecting member 220.
When the desired compression or separation distance between
vertebrae 222, 224 has been obtained, anchor 222 can be tightened
with fulcrum 120 to secure connecting member 220 between anchors
222, 224. When secured, connecting member 220 maintains the
vertebrae in the desired position and with the desired compression
attained through use of compression system 130.
[0053] A distraction system 160 will be discussed with reference to
FIGS. 15-22. Distraction system 160 includes a low profile
footprint positionable through portal 200 and engageable to
vertebrae to distract the vertebrae relative to one another.
Distraction system 160 includes a distractor 140 employed with a
fulcrum, such as fulcrum 70 discussed above, which are leveraged
off of one another to provide a mechanical advantage in delivering
the distraction force to the vertebrae through portal 200.
[0054] In FIGS. 15 and 16 there is shown distractor 140 including
an elongated body 142 extending along a longitudinal axis 141
between a proximal end 144 and a distal leverage surface 146. An
angled distal extension 148 extends distally along longitudinal
axis 149 from leverage surface 146 to a distally extending engaging
member 150. Longitudinal axis 149 is angled relative to
longitudinal axis 141 to angularly offset proximal end 144 from
engaging member 150. Engaging member 150 includes a flat,
plate-like arm to facilitate positioning between anchors at the
surgical site. A distally facing recess 152 is formed in a distal
end of engaging member 150.
[0055] Body 142 and angled extension 148 include a convexly curved
outer surface 158 to facilitate gripping by the surgeon. Opposite
outer surface 158 body 142 defines a proximal channel 154, and
angled extension 148 defines a distal channel 156. Channels 154,
156 are in communication with one another and extend along
respective ones of the longitudinal axes 141, 149 of body 142 and
angled extension 148. Channels 154, 156 can be defined by a
concavely curved surface as discussed above with respect to
compressors 40, 90. Channel 154, 156 can form a U-shaped receptacle
sized to receive elongated shaft 72 of fulcrum 70 therein.
[0056] A construct is positioned through the portal and engaged to
vertebrae, such as shown in FIG. 17. In the illustrated embodiment,
the construct includes anchors 212, 214 and connecting member 216.
Other embodiments contemplate other embodiment constructs as
discussed herein. Connecting member 216 is provided with one end
protruding from anchor 214 away from anchor 212 to provide a length
of connecting member 216 along which anchor 214 can move as the
distraction force is applied to the vertebrae.
[0057] A plug 215 can be engaged in anchor 212 to firmly secure
connecting member 216 therein, and a plug can be loosely positioned
relative to connecting member 216 in anchor 214. In FIG. 18 fulcrum
70 is positioned through portal 200 and its distal engaging member
76 is mounted to anchor 214. In FIG. 19 distractor 140 is
positioned through portal 220 so that engaging member 150 is
located between anchors 212, 214, and connecting member 216 is
received in recess 152. Distal channel 156 is positioned about
elongated shaft 72 of fulcrum 70, as shown in FIG. 20. Fulcrum 70
is nestably received relative to distractor 140 to facilitate
maintaining the distractor 140 and fulcrum 70 in contact with one
another and in alignment during distraction.
[0058] In this initial pre-distraction configuration, proximal end
144 of distractor 140 is spaced from proximal end 74 of fulcrum 70,
as shown in FIG. 19, due to the angular offset between elongated
body 142 and angled extension 148. Leverage surface 146 is located
at the junction between proximal channel 154 and distal channel 156
to provide a contact location for distractor 140 against shaft 72
of fulcrum 70. Engaging member 150 is offset away from distal
channel 156 so it can be positioned between anchors 212, 214
without interfering with engaging member 76 of fulcrum 70. Leverage
surface 146 can be positioned against shaft 72 at any one of a
number of locations therealong depending on the separation between
anchors 212, 214, the angle of approach to the construct taken with
distractor 140 and fulcrum 70, the angle of approach taken with
portal 200, and other factors.
[0059] To distract the vertebrae, proximal end 144 of distractor
140 is moved from its initial configuration toward proximal end 74
of fulcrum 70, as shown in FIG. 21. Distractor 140 pivots relative
to fulcrum 70 about leverage surface 146 to move engaging member
150 and engaging member 76 away from one another as further shown
in FIG. 22. This movement causes anchor 214 to slide along
connecting member 216 as the vertebrae are distracted. When the
desired distraction has been obtained, a driving tool can be
positioned through passage 75 of fulcrum 70 to secure the plug in
anchor 214 against connecting member 216 to post-operatively
maintain the distraction of the vertebrae.
[0060] While the invention has been illustrated and described in
detail in the drawings and foregoing description, the same is to be
considered as illustrative and not restrictive in character, and
that all changes and modifications that come within the spirit of
the invention are desired to be protected.
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